I have an extra cowboy server running in 8383 port in my Phoenix project. From my 4000 port I am trying to call an api to the 8383. But it throws error saying [Error] Preflight response is not successful. To fix this, how can I use a CORS Plug in the additional cowboy server. My application.ex code is given below:

defmodule MyApp.Application do
  # See https://hexdocs.pm/elixir/Application.html
  # for more information on OTP Applications
  @moduledoc false

  use Application

  def start(_type, _args) do
    children = [
      # Start the Ecto repository
      MyApp.Repo,
      # Start the Telemetry supervisor
      MyAppWeb.Telemetry,
      # Start the PubSub system
      {Phoenix.PubSub, name: MyApp.PubSub},
      # Start the Endpoint (http/https)
      MyAppWeb.Endpoint,
      Plug.Cowboy.child_spec(
        scheme: :http,
        plug: MyAppWeb.TestSocket,
        options: [
          dispatch: dispatch(),
          port: 8383
        ]
      ),
 # Start a worker by calling: MyApp.Worker.start_link(arg)
      # {MyApp.Worker, arg}
    ]

    # See https://hexdocs.pm/elixir/Supervisor.html
    # for other strategies and supported options
    opts = [strategy: :one_for_one, name: MyApp.Supervisor]
    Supervisor.start_link(children, opts)
  end

  # Tell Phoenix to update the endpoint configuration
  # whenever the application is updated.
  def config_change(changed, _new, removed) do
    MyAppWeb.Endpoint.config_change(changed, removed)
    :ok
  end

  defp dispatch do
    [
      {:_,
       [
         {"/account/:serial", MyAppWeb.TestSocket, []},
         {"/api/account/:serial/command", MyAppWeb.TestRouter, []}
       ]}
    ]
  end
end